This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Sinusitis, an inflammatory disease that affects the paranasal sinuses affects 33 million Americans. Some studies estimate that up to one in Americans will suffer from sinusitis per year. The etiology of sinusitis remains elusive and there is evidence to suggest that the multiple factors contribute to the development of chronic sinusitis. We hypothesize that a subset of chronic sinusitis is mediated by exposure to aeroallergens and inflammatory inducing particulate matter. Earlier we showed with hyperpolarized helium-3 MRI that the opening size significantly affected gas exchanged between the nasal cavity and paranasal sinuses and that small hole surgery may be preferable in patients with the class of sinus disease. Initially we thought that gas exchange in the small hole limit was mediated solely by the diffusion process, as hole size increased pressure induced airflow becomes dominant. We performed computation fluid dynamic simulation on phantom samples to test this hypothesis. It appears that even at small hole sizes ball flow occurs which may increase gas exchange under certain geometries.